The present invention relates to an eccentric grinder of the type provided with means for changing a grinding motion.
Eccentric grinders of the foregoing type include a grinding disc eccentrically positioned in respect to a drive shaft of the grinder motor. Such eccentric grinders have been available on the market and have been disclosed, for example in "Fachberichte fur Metallbearbeitung", Apr. 3, 1983, with the title "Rotex, die neue Dimension des Schleifens". Despite known advantages of such eccentric grinders an optional adjustment of such a grinder to practical requirements has not been possible. The gap between the pure course grinding and fine grinding has been too large. To avoid such a problem it has been suggested to provide a further drive stage with different diameters of the friction or toothed gears; this however has been conceivable only with a considerable enlargement of the structural components of the drive. Otherwise, the switching from one type of the drive to another type of the drive has always involved a big expense on the adjustment means. Such adjustment means must be robust and thus large for the drive but should, however be not succeptible to damage. With the utilization of the toothings on the grinding plate, the teeth of the toothings can be however damaged if the personnel is careless.